<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>弹性布局</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        .box {
            display: flex;
            /* display: inline-block; 行内块级 */
            background-color: red;
            height: 100px;
            width: 50%;
            margin-bottom: 10px;
        }

        .box:nth-child(2) {
            background-color: blue;
        }
        .item {
            flex: 1;
            background-color: green;
            font-size: 20px;
            color: black;  
            /* display: inline-block; */
            /* width: 33.33%; */
        }
        .item:nth-child(odd) {
            background-color: yellow;
        }
    </style>
</head>
<body>
    <div class="box">
         <div class="item">1</div>
         <div class="item">2</div>
         <div class="item">3</div>
    </div><div class="box"></div>
</body>
</html>